1. Field of the Invention
The present invention relates to a motorcycle in which fuel can be heated at engine start-up.
2. Description of the Related Art
Recently, vehicles with engines that are capable of using a blended fuel of gasoline and alcohol have been developed. Because the alcohol in the blended fuel is less likely to evaporate compared to the gasoline, the higher the concentration of the alcohol in the fuel is, the more deteriorated the starting characteristics of the engine are. In particular, the starting characteristics of the engine are more likely to deteriorate when the environmental temperature is low.
Therefore, a starting device that improves the starting characteristics at low temperature by heating the fuel in a fuel pipe at start-up has been disclosed. (See, for example, JP 2008-274825 A).
In the starting device described in JP 2008-274825 A, the fuel in the fuel pipe is heated by a heater. On the basis of the temperature of cooling water and the standing time from engine stop to engine re-start, the degree of heating the fuel by the heater is determined. This prevents the fuel from being overheated at start-up.
However, in motorcycles, an insufficient amount of fuel in the fuel pipes may occur under a variety of situations that are different from four-wheel motor vehicles. If the heater operates without enough fuel in the fuel pipe, the fuel in the fuel pipe is overheated. In this case, a required amount of the fuel for start-up is unlikely to be supplied due to vapor generated in the fuel pipe. Further, the controllability of the temperature of the fuel deteriorates since the temperature of the fuel rises above a required temperature.